The invention relates to a metal implant, by way of example for bones, the implant having a surface with a coarse structure of elevations and depressions, and to methods for producing the surface.
U.S. Pat. No. 4,673,409 and the U.S. Pat. No. 4,608,052 show a surface in which, starting from a smooth metal surface, pillars are produced by the material in that a laser is used to liquefy and vaporize material around the pillars in the form of channels of cylindrical blind holes placed adjacent to one another in a row. The upper faces of these pillars, which lie in the originally smooth metal surface, form support surfaces for a primary anchoring in the bone tissue; and the hollow spaces surrounding them can accommodate bone tissue that grows in later or bone cement. This type of metal processing is enormously complicated and expensive since the excess material must be vaporized at the low efficiency of a laser and since the focal point of the laser optics must continually be adjusted very precisely in its distance to the surface. Furthermore, during the spontaneous melting and vaporization, metal sprays arise which are in no regard desirable so that
U.S. Pat. No. 5,264,530 proposes to apply a protective coating prior to the laser drilling which can later be removed and which is also bored through and which prevents liquid metal sprays from striking the surface that it covers. Solvent soluble binders with metallic oxides which are heat resistant at high temperatures are considered as typical protective coatings. Nevertheless it is, of course, not possible to prevent metal sprays being deposited in the already cut channels.